The present invention relates to a manufacturing technique of a resin-sealed semiconductor device and, particularly, to a technique effectively applied to a semiconductor device suitable for high-density mounting like a multi-chip package, in which a plurality of LSI chips are embedded in one package.
With demands for the reduction in size of a semiconductor package in recent years, there has been a demand for a semiconductor device of the type generally called a multi-chip package (hereinafter “MCP”) or system-in package in which a plurality of LSI chips are embedded in one package. One example of such an MCP structure is a stacked structure in which two LSI chips are, for example, stacked and resin-molded to form a package. A concrete example of an MCP with the stacked structure is an MCP of a QFP (Quad Flat leaded Package) type in which LSI chips are stacked in the package, such as disclosed in the gazette of Japanese Patent Laid-Open No. 2001-267488, etc. The MCP of this type includes: a plurality of stacked LSI chips; a plurality of wires to electrically connect electrode pads of the LSI chips and external connection leads; a resin sealing body, formed by resin-mold, sealing a plurality of inner leads; and outer leads led out from the side surfaces of the resin sealing body. The resin sealing body is mounted to a mounting board by these outer leads. Also, another example of an MCP is of a so-called CSP (Chip Size Package) type, such as described in the gazette of Japanese Patent Laid-Open No. 11-204720, in which a plurality of LSI chips are stacked on a wiring board made of epoxy or polyimide and electrode pads of the respective LSI chips and electrodes on the wiring board are electrically connected by wire bonding or face-down bonding and the respective LSI chips on the wiring board and the electrically connected portions thereof are molded in resin (i.e., resin-sealed).